Knock-down structural member with collapsible members



7 Feb. 24,1959 MQL. CLEVETT, JR 2,874,812 7 KNOCK-DOWN'STRUCTURAL MEMBEWITH COLLAPSIBLE MEMBERS Fiied Jun 28', 1955 INVENTOR.

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ATTUENEY Y United States Pate KNOCK-DOWN STRUCTURAL MEMBER wrrnCOLLAPSIBLE MEMBERS Merton L. Clevett, In, East Natick, Mass.Application June 28, 1955, Serial No. 518,701

1 Claim. (Cl. 189-34) (Granted under Title 35, U. S. Code(1952), sec.266) tremely lightweight, strong knock-down structural member for use informing beams, columns, arches and the like in building construction,and the like. i

A further object is to provide a structural member of theabove-mentioned type which may be rapidly assembled and disassembledwith a minimum of time andlabor} and without the use of special tools.

A further object is to provide a knock-down construction member havingelemental sections or units formed from fiat foldable blanks of plasticreinforced cardboard, sheet metal or the like.

Another object is to provide a'knock-down construction member which willoccupy extremely little'space when packaged for shipment or storagewhile'in the disassembled and collapsed condition.

A still further object is to provide a structural member of theabove-mentioned type which may be used to form a substantiallysmooth-surfaced beam, pole or the like, free from surface projectionsand gaps.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings, forming a part of this application, andinwhich like numerals are employed to designate like parts throughout thesame,

Fig. 1 is a side elevation of a structural beam, or the like,constructed in accordance with the present invention,

Fig. 2 is a similar view of a column or pole. in accordance with theinvention,

Fig. 3 is a side elevation of an arch member in accordance with amodification of the invention,

Fig. 4 is a plan view of a sheet material blank utilized to form theelementalsections of the structural member,

Fig. Sis a transverse horizontal section taken on line 5-5 ofFig. 6, j

Fig. 6 is a transverse vertical section taken on line 6-6 of Fig. 5,Fig, 7 is a similar section taken on line 77 of Fig. 5, and

Fig. 8 is an enlarged fragmentary longitudinal vertical section throughthe arch shown in Fig. 3.

In the drawings, where for the purpose of illustration are shownpreferred embodiments of the invention, attention is directed first toFigs. 1, 2, and 4 to 7, inclusive, wherein'the numeral 10 designatesgenerally a knockdown, foldable structural member in accordance with theinvention, adapted to serve as a beam, joist, rafter, or the like, whenarranged horizontally as in Fig. 1, and as a pole, column, or the likewhen arranged vertically as in Fig. 2.

z The structural member 10 comprises a plurality of separate thin-walledbox-like elemental sections 11, arranged in end-to-end interfittingrelation, in assembly, as will be fully described. Any desired number ofthe elemental sections 11 may be employed for making the beam of Fig. lor the column or pole of Fig. 2.

Each box-like elemental section 11 is preferably rectangular intransverse cross section, Fig. 5, and includes side walls 12, 13,14,,and 15, as well as end walls 16 and 17. Each box-like section 11 ispreferably constructed from a flat foldable blank 18, Fig. 4, formed ofplastic reinforced cardboard, paper, sheet metal, or any other suitablesheet material capable of being bent or folded and possessing thedesired rigidity and stiffness. The blank 18 comprises asubstantiallyrectangular body portion 19 having three equi-distantlyspaced parallel fold or score lines 20 .extended thereacross fordefining in the blank element rectangular sections which are the sidewalls 12, 13, 14, and 15 when the blank is folded into the box-likesection -11, previously mentioned. The blank 18 further embodies a pairof extensions at opposite ends of the blank section or side 14, Fig. 4,foldable upon fold or score lines 21, and these extensions are the endwalls 16 and 17 of the assembled elemental box-like section 11.

The side or section 12 of the blank.18 is provided near its oppositeends with companion pairs of slits 22, and near and inwardly of itsouter edge with longitudinally spaced pairs of slits 23. The blanksection 12 also carries a narrow longitudinal flap 24 at its outerlongitudinal edge, foldable upon a fold or score line 25. The blanksection 15 carries at its outer longitudinal edge a pair oflongitudinally spaced tabs 26, insertable through the pairs of slits 23when the blank is folded to make the elemental box-like section 11.. Theblank extensions or ends 16 and 17 are similarly provided at theirextremities with transversely spaced tabs 27, insertable through thepairs of slits 22 when the blank is folded for making the elementalbox-like sections 11 of the structural member 10. The blank extensions16, which as previously stated are the end walls 16 of the sections 11are suitably embossed to form thereon short conically tapered truncatedprojections or hollow bosses 28, integral therewith. Each projection 28has a central aperture 29 formed in its end Wall, as shown. Theextension 17 of each blank 18 is likewise centrally embossed to providein the end wall 17. of.each elemental section 11 a conically taperedtruncated hollow projection or boss 30 having a central aperture 31formed therein as shown, for axial alignment with the aperture 29 in thefolded blank. 7 1 In constructing each box-like elemental section 11,the blank sections 13 and 15, Fig. 4, are folded upwardly along thescorelines 20 and the blank section 12 is then folded along one score line 20until it is arranged opposite the blank section 14 and at right anglesto the blank sections 13 and 15. The narrow flap 24 is now turnedinwardly at right angles to the section 12 and disposed upon the innerside of the side wall 15, Fig. 5. The tabs 26 are now passed through thepairs of slits 23 in the manner shown in the drawings. The blankextensions 16 and 17 are now folded on the score lines 21 to opposedparallel relation, at right angles to the sections or sides 12, 13, 14,and 15, and the tabs 27 are passed through the pairs of slits 22 in themanner shown in the drawings for completing the construction of thehollow box-like elemental section 11.

The completed elemental section 11, Fig. 7, is somewhat elongated andrectangular in transverse cross section and is generally similar inshape to the well-known wax-coated paper quart milk carton. In thecompleted section 11, the hollow boss or projection 28 projects hea)yond or outwardly of the end wall 16, Fig. 7, and the hollow projection30 projects inwardly of the end wall 17 to form in the corresponding endof the elemental section 11a conicallyjapered truncated ,recess adaptedto snugly receive the projection 28 of acompanion elemental section 11in the structural member 10.

In the member 10, means are provided for securing the elemental sections11 together under tension in end-to-end interfitting relation. Suchmeans comprises a flexible cable or element 32 of desired length, havingpermanently secured to ,one end thereof by any suitable means acylindrical screw-threadedrod 33. The opposite end of the cable32 has acylindrical pin 34 permanently secured thereto by any suitable means,and the pin 34 is provided at its outer end with a flat circular head35, preferably formed integral therewith.

A desired numberof the box-like sections 11 are placed in end-to-endrelation with the tapered projections 28 at corresponding ends thereofinterfitting with the recesses in the other corresponding ends of thesections, afforded by the projections 30. The sections 11 are orientedso that their side walls form on the structural member four continuousand substantially smooth or uninterrupted side walls, whereby the entiremember 10 is rectangular in cross section.

A base or end plate 36 is provided for oneend of the member 10 and thisbase-plate is provided upon one side with a conically tapered truncatedprojection 37, corresponding in shape and size to each projection 28,and adapted to fit within the recess afforded by the project- .tion 30of the endmost elemental section 11 of the member 10. The end plate 36has an opening 38 formed axially therethrough, and is further providedin its outer side with a counterbore or recess 39, receiving the head35, whereby the head is flush with the outer side of the end plate .36.

In assembling the structural member 10, the screwthreaded rod 33 andcable 32 are threaded axially through the interiors of all of thebox-like sections 11 and through all of the openings 29 and 31 of theprojections 28 and 30 which register in assembly. The pin 34 will engagethrough the opening 38 of the end plate 36, and through the opening 31of the endmost elemental section 11, Fig. 6. The endplate 36 preferablyhas a swiveled connection with the pin 34.

After the cable and rod 33 are threaded entirely through all of theelemental sections 11, a large nut 40 having a central screw-threadedopening 41 formed therethrough is applied to the screw-threaded rod 33.This nut 40 is provided in its inner face with a truncated conicallytapered recess 42, snugly receiving the projection 28 of the adjacentendmost elemental section 11, Fig. .6. When the nut 40 is tightened, itbears against the adjacent end of the endmost section 11 and the cable32 is placed under tension and the end plate 36 is drawn against theadjacent end of the other endmost section 11. This firmly securestheseveral sections 11 together in end-toend interfitting relation, andthe resulting beam or pole shown in Figs. 1 and 2, respectively, issubstantially rigid and very strong, so as to have utility in buildingconstruction, aircraft construction and the like.

I also contemplate forming the projections 28 and 30 other than circularor conical in cross section, and these projections may be formedrectangular or 'inthe shape of truncated pyramids in cross section, ifdesired. If this is done, the interfitting projections 28 and 30 willautomatically orient the flat sides 12, '13, 14, and of the elementalsections 11 in parallelism in assembly, and it will be unnecessary toassemble the member 10 on a 4 flat surface or otherwise arrange thesections 11 by hand so that the completed member 10 will be rectangularin cross section and have substantially smooth or continuous sides, freeof gaps or projections.

In Figs. 3 and 8, I have shown a modification of the invention, whereina desired number of the elemental sections 11 may be utilized .to forman arch member 10' for building construction or the like. To facilitatethis, I provide between the ends of each adjacent pair of sections 11tapered or wedge-like spacer elements 43 formed of molded plasticmaterial, or the like. Each spacer 43 has acentral opening 44 formedtherethrough for registration with a pair of the openings 29 and 31 inassembly, andadapted .to receive the cable 32. Each spacer element 43 isfurther provided upon one face with a truncated conically taperedprojection or boss 45 which snugly interfits within the recess affordedby the embossed projection 30 of one adjacent elemental section '11. Theopposite side of each spacer .element 43 has aztruncated conicallytapered recess .46 formed therein to receive the projection 28 on theend of the other adjacent elemental section 11.

It is thus seen that the use of the spacer elements 43 enables the sameelemental sections or units 11 employed in the straight structuralmember 10 to be utilized with the same cable 32 and associated parts forforming a curved arch member or beam such as the arch member 10, Fig. 3.

All other parts and their functions are identical with correspondingparts shown described in connection with the first form of theinvention.

It is to be understood that the forms of the invention, herewith shownand described are to be taken as preferred examples of the same, andthat various changes in the shape, size and arrangement of parts may beresorted to, without departing from the spirit of the invention or thescope of the subjoined claim.

I claim:

A knock-down arch or the like comprising a plurality of hollow box-likeelemental sections having ends provided with openings, projectionsformed upon corresponding ends of said sections, the other correspondingends of the sections having recesses formed therein, wedgelike spacersarranged between adjacent ends of said sections and having openingsformed therethrough registering with the openings of said ends,projections formed upon corresponding sides .of said spacers andinterfitting with said recesses of corresponding ends of the sections,the other sides of the spacers having recesses interfitting with saidprojections of corresponding ends of said sections, a flexible elementextending through'the interiors of said sections and through theopenings of said ends and spacers, and means connected with saidflexible element for tensioning the same and thereby drawing saidsections and spacers rigidly together in end-to-end interfittingrelation.

References Cited in the file of this patent UNITED STATES PATENTS233,271 McLean et al. Oct. 12, 1880 511,472 Sumovski Dec. 26, 18931,110,157 Stewart Sept. 8, 1914 2,705,015 Langlais Mar. 29, 1955 FOREIGNPATENTS 21,680 Sweden Dec. 15, 1906 377,715 France July 19, 1907 746,138France Feb. 27, 1933 1,052,362 France Sept. 23, 1953

